The present invention relates to a technique for processing magnetic resonance signals.
One known imaging technique using a magnetic resonance apparatus comprises performing reception of magnetic resonance signals by a body coil and reception of magnetic resonance signals by a surface coil, and reconstructing an image based on the magnetic resonance signals from both the body and surface coils.
According to the imaging technique, the magnetic resonance signals by the surface coil having the advantage in S/N (signal-to-noise) ratio are sensitivity-corrected based on the magnetic resonance signals by the body coil having the advantage in homogeneity of spatial sensitivity, for example, whereby an image can be obtained with high S/N ratio and at the same time without inequalities of sensitivity.
In recent years, there is proposed a variation of the imaging technique described above, that is, what we might call a concurrent reception technique, comprising concurrently receiving magnetic resonance signals by a body coil and a surface coil. Since the concurrent reception technique makes no temporal separation between reception by the body coil and that by the surface coil, there are provided advantages that the imaging time may be reduced and magnetic resonance signals by the coils may be received under the same environment. At that time, however, significant coupling usually occurs between the body coil and surface coil, which especially results in degradation of homogeneity of sensitivity in the body coil.
Accordingly, in performing the concurrent reception technique, hardware decoupling is generally applied, in which impedance of preamplifiers connected to the coils is brought close to zero, for example, to reduce such an effect.
However, there is a limit in hardware decoupling, thus often resulting in imperfect decoupling.
In view of such circumstances, there is a need for a technique in performing concurrent reception of magnetic resonance signals by a body coil and a surface coil using a magnetic resonance apparatus, with which decoupling between the coils can be effectively achieved.